This was not a mistake.

I assume that you think an angular-cli shouldn’t be part of the ember-ecosystem.
You are not the first person that suggests such a change. Right now there are similar pull requests to the other angular-cli addon, concerning the same:
IgorMinar/angular-cli-github-pages#1
IgorMinar/angular-cli-github-pages#3

Right now angular-cli is based on top of ember-cli.
Technically angular-cli-ghpages is still a 100% compliant ember-addon.
This might change in future. See angular/angular-cli#55

This plugin will run perfectly as a “normal” ember addon, too. It pushes stuff from ./dist (or any other folder) to any gh-pages (or any other branch) to any git repository. It’s valuable for every ember build. But yes, the name indicates a deep relation to Angular 2 builds.

I will keep the pull request open, so that it can be found easily.

Problem solved. This is not any longer a ember-addon.